Experts have devised an anti-grooming tool in a boost for Home Secretary Sajid Javid’s drive to combat online child abuse.

Engineers from some of the world’s biggest tech firms, including Microsoft, Facebook, Google, Snap and Twitter, worked for two days at a “hackathon” in the US last week.

Participants at the event, co-hosted by Microsoft and the Home Secretary, analysed tens of thousands of conversations to understand patterns used by predators.

The exercise yielded a prototype tool that can be used to automatically flag potential conversations taking place between groomers and children.

Once these exchanges are flagged, they can be investigated by a moderator.

Further work will take place on the prototype. Once completed it will be licensed free of charge to smaller and medium-sized technology companies worldwide.

Mr Javid (pictured) said: “We all have a responsibility to tackle online child sexual exploitation and the new tool developed during the hackathon is a positive step forward.

“Once complete, it will be rolled out for free to other tech companies that want to deploy it.

“This is just one thing we can do together to combat this appalling crime.”

The Home Secretary held talks with major tech firms about their efforts to tackle child sexual exploitation and remove abusive content from their sites.

Earlier this year he described his shock at discovering the scale of the danger posed by paedophiles on the internet.

In a speech in September he disclosed that the National Crime Agency estimated that around 80,000 people in the UK presented some kind of sexual threat to children online.

Referrals of child abuse images to the NCA have surged by 700% in the last five years, while separate figures suggest police in England and Wales record an average 25 child sexual offences involving the internet every day.